The I-V characteristics of the individual subcells of a monolithic Ga 0.50 In0.50 P/ Ga0.99 In0.01 As/Ge triple-junction solar cell have been extracted from measurements of the electroluminescence peak intensity as a function of the electroluminescence injection current. By using the spectral reciprocity relation between the electroluminescence and the quantum efficiency, the individual subcell I-V characteristics were derived. It is shown that the subcell dark I-V characteristics and the subcell illuminated I-V characteristics are accessible under variable spectral illumination conditions

Autonomous systems are increasingly used to provide situational awareness and long-term environment monitoring. Photovoltaics (PV) are favored as a long-endurance power source for many of these applications. To date, the use of PV is limited to space and terrestrial (dry-land) installations. The need for a persistent power source also exists for underwater (UW) systems, which currently rely on surface PV arrays or batteries. In this paper, we demonstrate that high-bandgap-InGaP solar cells can provide useful power UW.

No abstract

No abstract

Lattice matched InAlGaAs tunnel junctions with a 1.18 eV bandgap have been grown for a triple-junction solar cell on InP. By including two InGaAs quantum wells in the structure, a peak tunnel current density of 113 A/cm2 was observed, 45 times greater than the baseline bulk InAlGaAs tunnel junction. The differential resistance of the quantum well device is 7.52 × 10−4 Ω cm2, a 15-fold improvement over the baseline device. The transmission loss to the bottom cell is estimated to be approximately 1.7% and a network simulation demonstrates that quantum well tunnel junctions play a key role in improving performance at high sun-concentrations.

No abstract

No abstract

No abstract